4x4 Noise

[briandelaney]

I have a 2003 Sport trac. I am getting a Humming/whining noise in the front Left when the truck is in 4x4 high.

Noise starts at about 30-35mph and gets a little louder at 40 mph.

I had the Front Hubs/Wheel Bearings replaced on both the L&R side and the front transfer case drained and refilled a month ago in hopes of solving the problem but I am still getting the noise. As soon as I turn off the 4x4 the noise goes away.

Fortunately, I have an ESP on it until August so I am trying to figure out what this could be before the ESP runs out but the Dealership is useless in figuring it out.

Any ideas

 

[ncranchero]

Bound to be a bearing and if the hubs/bearings were replaced all that's left is the front differential bearings. I don't really think the half-shafts would whine, not that I've ever heard. Have you swapped tires front to back?

 

[briandelaney]

Thanks, I'll start with the tires and see where it leads, I'll let you know

 

[mbautodesign]

my 02 does the same thing
havent really looked into it, i hardly ever use 4wd anymore
i also have brand new front bearings from ford installed last year